Dylan Efron lit up the stage on "Dancing with the Stars" Tuesday night -- but it was his brother, Zac Efron , who stole the show while sitting in the audience! That's right ... Dylan's big bro Zac made it to the ballroom to watch him perform an energetic tango to "I Would Die 4 U" with his partner, Daniella Karagach . Zac sat with the bros' baby sister Olivia on his lap in the audience. The hunky actor also had fans cracking up online after the judges gave Dylan an impressive 27 out of 30 score